In case of a new standard for processing, e.g. recording, data, or in case of a new upgraded version of such standards, records of recording devices working according to that new standard or version are not readable by recording devices of an older version.
According to some standards version numbers are used to indicate the version of its assigned recorded information. If a device detects information indexed by a higher version number than the version number supported by the device itself, then this device will reject this information, because the device does not know anything about the structure of this information. This has the effect that the device is not able to access to the information and will stop any further processing of the information.
However, it is important to take care of future versions of a standard. If there is taken no care of later versions, then the behaviour of the older devices may be arbitrary in the case of handling version updated information. Arbitrary behaviour of older devices, or such non-existence of forward compatibility is a big disadvantage.